Machine for cleaning blackboard-erasers.



0 G. U. THOMPSON. MACHINE FOR CLEANING BLAGKBOARD ERASERS.

APPLICATION FILED NOV. 20, 1911.

1,070,304, Patented Aug. 12,1913.

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'-L0z'tnesses: Inventor,

Grant U. Thompsonfllvy Attorrnzg.

UNITED STATES PATENT OFFICE.

MACHINE FOR CLEANING BLACKBOARD-ERASERS.

Specification of Letters Patent.

Patented Aug. 12,1913.

Application filed November 20, 1911. Serial N 0. 661,266.

To (ZZZ whom it may concern:

Be it known that I, GRANT U. THOMPSON, a citizen of the United States of America, and a resident of Cedar Falls, Blackhawk county, Iowa, have invented certain new and useful Improvements in Machines for Cleaning Blackboard-Erasers, of which the following is a specification.

My invention relates to improvements in machines for cleaning blackboard erasers, and the object of my improvement is to furnish for use in schoolhouses, an apparatus adapted to receive a quantity of such erasers and cleanse them from chalk-dust, thor oughly, while confining the dust to the in terior of the apparatus, and having means for conducting the collected dust into a detachable receptacle, and said apparatus also having means for muffling the noise of its operation. This object I have accomplished by the mechanism which is described and claimed in the following specification, and which is illustrated in the accompanying drawings, in which:

Figure 1 is a front elevation of my improved machine for cleaning blackboard erasers, with the drum and fan-chamber and receptacles in medial vertical longitudinal section. Fig. 2 is an elevation of the lefthand end of said apparatus, with the fanchamber and its conduit in vertical transverse section on the line ab of Fig. 1, and a part of the drum shown broken away to disclose its interior. Fig. 3 is a right-hand end elevation of said machine.

Similar numerals of reference designate corresponding parts throughout the several views.

My machine comprises a hollow rotary drum 1, whose inner periphery may be longitudinally corrugated as shown in order to .provide means for engaging and carrying up erasers placed in the drum. vThe drum has in its circumference a door-opening adapted to be closed by a swing-door 18, secured to the drum by hinges 24:, and arranged to be detachably secured thereto when closed by means of hooks 25 hung on eyelets 26 and detachably engaging eyelets 27, although other fastening means may be used as found desirable. Secured to the heads 5- and 30 of said drum and extending across the interior of the drum are the rods 4, and any desired number may be used, and they may be crossed as shown, but when crossed the rods should be spaced apart from each other plurality to prevent interference with the movements of the erasers in falling across the drum while the latter is in rotation. Thesecrossbars aid in the extraction of, the chalk-dustfrom the erasers. by interposing in their paths when falling, thus giving the erasers a more thorough agitation by reason. of the of contacts during each rotation of the drum. I

The drum is supported by the'legs 16 and 22, the right-hand end or head 30 of the drum having an axial sleeve secured about a short shaft 20, the latter rotatable in a bearing at the. upper junction of the legs 22. The left-hand end or head 5 of said drum has an outwardly-projecting axial sleeve 6' of a considerable diameter, and which is roand 22 are rigidly connected by bars 17 and 29. A rotary fan-shaft 9 traverses the interior of the fan-chamber 11 horizontally and seated in hearings in the walls of said chamber, and the outwardly-projecting part of said shaft is carried under thedrum 1, parallel thereto, and has its right-hand end seated in a bearing 33 secured and supported on a cross-bar 34 fixed between and to the legs 22. Upon the right-hand end of the shaft 9 is a small sprocket-wheel 32, while upon the left-hand end of said shaft within the chamber 11 is a fan-Wheel 10. A larger sprocket-rim 31 is concentrically mounted upon the right-hand head 30 of sald drum, while a sprocket-chain 23 operatively connects the sprocket-rim 31 and the smaller sprocket-wheel 32, the drum having a handcrank 21 secured to its axial shaft 20. Whereby it is rotated, and the said sprocket-rim 31 is-by said chain induced to rotate the wheel 32 with the shaft9 and the fan-Wheel 10 thereon, to induce a more rapid rotation of the latter. Y

The right-hand drum-head 30 is provided with a plurality of small-air-inlet orifices 28. The fan-chamber 11 has a downwardlydirected spout 12 adapted to enter the boxcasing 13 and also the neck of an inner receptacle 15, detachably but closely fitted thereto. The Walls of the inner receptacle or vessel 15 are porous, being}; made of cloth or other suitable material adapted to receive chalk-dust and retain it while at the same time permitting, exit by Way of its interstices to the exhausted air driven from the fan-wheel 10. The outer box or casing 13 has in its sides openings which are covered by meshed material such as loosely woven wire or cloth, to provide a secondary filtering means for the exhausted dust-carrying air, while permitting transpiration of the air alone. When a number of chalk-filled erasers have been deposited in said drum and the closure therefor secured, the drum then being put in rotation and the fan-wheel actuated by the al'Jove-described means, the erasers are carried upward by the inner corrugated walls of the drum, and in falling, more or less contact with the cross-bars 4, and by these means the dust is thoroughly knocked out of the pads, renovating the pads in the process, by restoring them to their original extendedshape from their compressed shape induced by the matting of use. The fan-whee1 being in very rapid rotation is adapted to draw a current of air into the drum by way of the ports 28, and these currents in traversing the interior of the drum, take up the chalk-dust and then the dust-laden air is drawn out of the drum by the action of the fan through the conduit 7' and chamber 11 to be finally deposited in the receptacle 15. The drum 1 is supplied with an outer spaced apart retaining shell 3, and the space between said shell and the drums exterior circmnferential surface is filled with any suitable sound-mufiiing 1naterial 2, and this kind of muflling-means may be carried about the heads of the drum if desired. a

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is:

In combination, a rotary longitudinally ribbed drum having a door-opening, a closure hinged to said drum and'adapted to close said opening, meansfor securing said door detaehably over said opening, means for rotating said drum, said drum being provided in one head with an air inlet and in the opposite head with an air exit, airexhausting means in communication With said air-exit, and operative driving connections between said rotating-means and said air-exhausting means.

Signed at Waterloo, Iowa, this 7th day of Nov. 1911.

GRANT U. THOMPSON.

Witnesses:

W. H. BRUNN, Gr. G. KENNEDY. 

